改良CT测量法用于椎弓根螺钉个体化植入的实验研究

[目的]探讨进钉点到棘突中心矢状面的垂直距离用于椎弓根螺钉个体化植入的可行性.[方法]于华中科技大学同济医学院解剖教研室收集成人脊柱标本30例,在CT横断面扫描图像上测量如下数据:椎弓根宽度a,进钉点到椎体前缘的距离b,进钉点到棘突中心矢状面的垂直距离c,椎弓根纵轴与椎体矢状轴的夹角A,在侧位片上测量椎弓根纵轴与操作台垂直线的夹角B,分为实验组和对照组,实验组采用CT图像上进钉点到棘突中心矢状面的垂直距离用于进钉点在水平方向上的定位,对照组采用Ebraheim法定位进钉点,置钉后行CT扫描,判断螺钉有无穿破椎弓根内侧或外侧壁及穿破程度,按照穿破程度进行分级:A=完全位于椎弓根内;B:穿破程度＜2 mm;C=穿破程度2～4 mm;D=穿破程度＞4 mm,并进行对比分析.[结果]实验组T3-10水平螺钉穿破率明显低于对照组,T1,T2,T 11,12:两组的穿破率相当.在T 3-18水平,螺钉的穿破程度(C,D级)明显高于其他节段,与椎弓根在这些节段横径变小有关;T 1-12,实验组中C,D级的发生率低于对照组.[结论]采用进钉点到棘突中心矢状面的垂直距离用于定位椎弓根螺钉进钉点,可以明显提高螺钉在水平方向上的植入准确性.尤其在L 3-10节段,而且特别适合由于解剖变异,外伤,肿瘤破坏等原因使关节突关节,横突等解剖标志发生改变时椎弓根螺钉的植入,亦可以在正常解剖情况下作为传统定位方法的有效补充.     

术前CT测量在胸腰椎骨折椎弓根钉植入中的应用

胸腰椎骨折经椎弓根短节段固定进钉点和进钉方向的选择是关键。因为椎弓根内侧壁距脊髓或马尾只有2-3mm，下缘有神经根通过。螺钉穿破椎弓根的内侧壁或下壁，可造成脊髓或神经根损伤．同时在同一椎体因进钉点错误再重新调整较困难．使短节段固定无法进行l。正确植入椎弓根螺钉不仅与术者的临床经验有关，     

颈胸段脊柱侧块螺钉和椎弓根螺钉的抗拔强度的研究

目的　分析颈胸段脊柱后路不同置钉方法的拔出强度。方法　 5例新鲜尸体脊柱C6～T4椎骨 ,分解为单个椎体 30个 ,共 6 0个椎弓根。对其中的颈椎分为两组 ,分别为侧块螺钉固定组 (Roy -Camille法 ,Magerl法 ,Anderson法 ,自行设计侧块螺钉植入法 )和椎弓根螺钉固定组。将 6 0个椎弓根分组进行拔出测试 (5mm/min的速度垂直方向拔出 )。胸椎全部用椎弓根螺钉固定。结果　Roy-Camille法和Magerl法最大的拔出力接近 ,自行设计侧块螺钉植入法较Magerl法明显增加 ,而椎弓根螺钉抗拔出力最大。结论　选用侧块后正中线中下 1 / 3作为进针点 ,其抗拔出强度明显增加 ,钉道增加 ,操作简便 ;而颈胸椎椎弓根螺钉的拔出强度均大于侧块螺钉     

胸腰椎椎弓根螺钉误置的原因分析及对策

目的 探讨胸腰椎椎弓根螺钉误置的原因及对策。方法 1996-2002年对293例脊柱疾病患者施行椎弓根螺钉内固定术发生的螺钉误置情况进行回顾性总结，分析。结果 293例共置入椎弓根螺钉1256枚，螺钉植入节段错误7例，占2.38%；上胸椎（T2-7）置钉113枚，有11枚螺钉穿破椎弓根皮质，占9.74%；下胸椎（T8-12）置钉261枚，有9枚螺钉穿破椎弓根皮质，占3.45%；腰骶椎置钉882枚，有16枚穿破椎弓根皮质，占1.81%，共计36枚螺钉，占2.87%；螺钉角异常65枚，占5.81%。结论 椎弓根螺钉误置与操作技术，解剖学变异及脊柱病损因素密切相关；良好的手术技巧，术前影像资料的认真观测及术中必要的影像监控是准确置钉的关键。     

颈胸段脊柱侧块螺钉和椎弓根螺钉的抗拔强度的研究

目的 分析颈胸段脊柱后路不同置钉方法的拔出强度。方法 5例新鲜尸体脊柱G6～T4椎骨，分解为单个椎体30个，共60个椎弓根。对其中的颈椎分为两组，分别为侧块螺钉固定组(Roy-Camille法，Magerl法，Anderson法，自行设计侧块螺钉植入法)和椎弓根螺钉固定组。将60个椎弓根分组进行拔出测试(5mm／min的速度垂直方向拔出)。胸椎全部用椎弓根螺钉固定。结果 Roy-Camille法和Magerl法最大的拔出力接近，自行设计侧块螺钉植入法较Magerl法明显增加，而椎弓根螺钉抗拔出力最大。结论选用侧块后正中线中下1／3作为进针点，其抗拔出强度明显增加，钉道增加，操作简便；而颈胸椎椎弓根螺钉的拔出强度均大于侧块螺钉。     

三维CT重建模拟三种腰椎椎弓根螺钉置入方法的安全性分析

目的：通过计算机三维CT重建，测量三种腰椎椎弓根螺钉置入方法的置钉参数，探讨其安全适用节段。方法：在40例腰椎CT三维重建图像上应用人字嵴顶点法、Magerl法及Roy-Camille法模拟置钉．测量进钉点至椎弓根轴线的距离及置钉水平面角的安全范围．比较三种方法在腰椎各节段安全性的差异。结果：在L1～L4。“人字嵴顶点法”的进钉点到椎弓根轴线距离小于它其两种方法（P〈0．05）；在L5，Magerl法的距离最短（P〈0．05）。在L1、L2．三种方法置钉水平面角（TSA）的安全范围无显著性差异（P〉0．05）；在L3、L4，“人字嵴顶点法”与Magerl法的置钉TSA的安全范围大于Roy-Camille法（P〈0．01）．但两者之间无显著性差异（P〉0．05）；在L5．Magerl法的安全范围最大（P〈0．05）。结论：在L1～L4，“人字嵴顶点法”是理想置钉方法：在L5，Magerl法是理想置钉方法：Roy-Camille法仅适合于L1、L2．不推荐在L3～L5应用。     

寰椎椎弓根螺钉置钉的解剖与临床研究

目的：建立和验证寰椎后路椎弓根螺钉固定的进钉技术。方法：利用40套干燥配套寰枢椎标本测量进钉技术的相关参数，而后临床应用该技术方法置钉并行X线、CT复查其准确性。结果：寰椎椎弓根平均宽度为7．78mm，进钉点在寰椎椎弓根中线外侧2．2m，螺钉进钉点可由经枢椎下关节突中点的纵垂线来确定；手术中该方法不仅能简化操作过程，而且术后检查发现螺钉均准确置入。结论：用枢椎下关节突中点作为术中判定寰椎椎弓根螺钉进钉点的方法准确可靠。     

术前CT测量在胸腰椎骨折椎弓根钉植人中的应用

胸腰椎骨折经椎弓根短节段固定进钉点和进钉方向的选择是关键.因为椎弓根内侧壁距脊髓或马尾只有2～3mm,下缘有神经根通过.螺钉穿破椎弓根的内侧壁或下壁,可造成脊髓或神经根损伤,同时在同一椎体因进钉点错误再重新调整较困难,使短节段固定无法进行[1].     

寰椎椎弓根螺钉进钉点的解剖定位研究

目的 建立简易可靠的寰椎后路椎弓根螺钉进钉点的定位技术。方法 设定寰椎椎弓根螺钉的进钉点,利用40套干燥配套寰枢椎标本,测量与进钉点相关的数据参数,分析数据之间的关系。结果 寰椎椎弓根螺钉进钉点和枢椎下关节突中线与后正中矢状面的距离分别是19.61mm、19.21mm,二者仅相差0.40mm。结论 枢椎下关节突中心点可作为术中判断寰椎椎弓根螺钉进钉点的解剖学定位标志。     

胸腰椎骨折椎改良椎弓根钉置入方法的解剖学研究

目的 从解剖学上研究胸腰椎骨折椎置入椎弓根螺钉的可行性,为胸腰椎骨折椎提供一种新的椎弓根螺钉固定方法.方法 利用50例配套T11、T12 L1、L2脊柱干骨标本,测量各椎弓根宽度和高度.设定改良骨折椎椎弓根螺钉的置入方法,确定椎弓根正中轴矢状面在椎体前下缘的交点为a点,椎弓根中点为b点,连接a b点,以此连线作为改良椎弓根钉轴.此连线延长线于附件后面的投射点为改良椎弓根钉进钉点.测量改良进钉点位置,钉轴长度、下斜角度和内斜角度等.结果 T11、T12L1和L2椎弓根上下1/2横径平均为7.5 mm、7.7mm、6.9 mm和6.7 mm,绝大部分可置人直径5 mm螺钉:改良椎弓根钉置入点位于Magel法进钉点上方5～6.5mm,进钉方向下斜(以下终板为参照)约25°,内倾约100°结论胸腰椎骨折椎置入椎弓根螺钉在解剖学上是可行的,骨折椎改良椎弓根钉置入方法可以应用于椎体后壁1/2处至椎体前下缘连线以上的椎体骨折,以增强固定的稳定性或减少固定节段.     

后路经伤椎单节段与双节段固定治疗胸腰段骨折疗效比较

目的比较后路经伤椎单节段与双节段固定治疗胸腰段骨折的临床疗效。方法将70例胸腰段骨折患者根据固定方式不同分为单节段组(采用后路经伤椎单节段固定,33例)和双节段组(采用经伤椎双节段固定,37例)。比较两组患者手术时间、出血量(术中失血量+术后引流量)、住院天数、围手术期并发症、术后24个月ODI、术后伤椎高度矫正率、术后24个月伤椎高度矫正丢失率、术后Cobb角矫正率及术后24个月Cobb角矫正丢失率。结果患者均获得随访,时间24个月。两组患者住院天数、术后并发症发生率、术后伤椎高度矫正率、术后Cobb角矫正率、术后24个月ODI等比较差异均无统计学意义(P0.05);两组患者的手术时间、出血量、术后24个月伤椎高度矫正丢失率、术后24个月Cobb角矫正丢失率比较差异均有统计学意义(P0.05)。结论后路经伤椎单节段与双节段固定治疗胸腰段骨折均能获得满意的临床疗效,单节段固定手术时间及出血量较少,双节段固定够有效恢复并维持椎体高度、减少术后后凸畸形矫正丢失。     

应用不同影像学检查方法评估椎弓根螺钉位置的研究

目的研究X线片、CT和MRI对术后胸腰椎椎弓根螺钉位置的影像判断特点,选择判断椎弓根螺钉位置准确性的最佳方法。方法选取6具正常成人尸体脊柱标本（T9-L5）,分别将108个钛合金的椎弓根螺钉植入标本椎弓根,然后分别摄X线片、CT和MRI扫描。随后由不知情的第三者阅片判断各个椎弓钉位置,再逐个轴位横断解剖脊柱标本以检查螺钉的实际植入位置。最后,评估各种评判方案的准确度。结果X线片组、CT组、MRI组和X线片加CT加MRI联合组的判定灵敏度分别是93.68%、95.79%、93.68%和97.89%。其判定特异度分别是23.08%、5 3.85%、46.15%和33.33%、63.64%、50.00%和81.82%。综合判定X线片组、CT组、MRI组和X线片加CT加MRI联合组的准确度分别是85.19%、90.74%、87.96%和94.44%。结论对于常规胸腰椎术后患者,单纯应用X线片判定术后椎弓根螺钉位置准确性是比较可靠的,但对于术后出现神经症状者应联合应用X线片加CT加MRI,以提高准确性。     

Solid and hollow pedicle screws affect the electrical resistance: A potential source of error with stimulus-evoked electromyography

Background:

Although stimulus evoked electromyography (EMG) is commonly used to confirm the accuracy of pedicle screw placement. There are no studies to differentiate between solid screws and hollow screws to the electrical resistance of pedicle screws. We speculate that the electrical resistance of the solid and hollow pedicle screws may be different and then a potential source of error with stimulus-evoked EMG may happen.

Materials and Methods:

Resistance measurements were obtained from 12 pedicle screw varieties (6 screws of each manufacturer) across the screw shank based on known constant current and measured voltage. The voltage was measured 5 times at each site.

Results:

Resistance of all solid screws ranged from 0.084 Ω to 0.151 Ω (mean =0.118 ± 0.024 Ω) and hollow screws ranged from 0.148 Ω to 0.402 Ω (mean = 0.285 ± 0.081 Ω). There was a significant difference of resistance between the solid screws and hollow screws (P < 0.05). The screw with the largest diameter no matter solid screws or hollow screws had lower resistance than screws with other diameters. No matter in solid screws group or hollow screws group, there were significant differences (P < 0.05) between the 5.0 mm screws and 6.0 mm screws, 6.0 mm screws and 7.0 mm screws, 5.0 mm screws and 7.0 mm screws, 4.5 mm screws and 5.5 mm screws, 5.5 mm screws and 6.5 mm screws, 4.5 mm screws and 6.5 mm screws. The resistance of hollow screws was much larger than the solid screws in the same diameter group (P < 0.05).

Conclusions:

Hollow pedicle screws have the potential for high electrical resistance compared to the solid pedicle screws and therefore may affect the EMG response during stimulus-evoked EMG testing in pedicle screw fixation especially in minimally invasive percutaneous pedical screw fixation surgery.     

微创经皮置钉技术治疗胸腰椎骨折的临床疗效

目的探讨微创经皮置钉技术(MIPPSF)治疗胸腰椎骨折的临床疗效。方法将89例单节段胸腰椎骨折患者按照椎弓根置钉方法分成MIPPSF组(A组,36例)和开放手术椎弓根螺钉内固定技术(OPSF)组(B组,53例)。比较两组患者切口长度、手术时间、术中出血量、术后3 d VAS评分、术后1年伤椎前缘高度比和矢状面Cobb角评价内固定失败率和Oswestry功能障碍指数(ODI)。结果患者均获得随访,时间12~18个月。两组切口长度、手术时间、术中出血量和术后3 d VAS评分A组均少于B组,差异均有统计学意义(P0.05);术后1年伤椎前缘高度比、矢状面Cobb角、内固定失败率和ODI两组比较差异均无统计学意义(P0.05)。结论 MIPPSF治疗胸腰椎骨折创伤小,治疗效果与OPSF相似。     

两种不同方法提高椎弓根螺钉稳定性的体外生物力学研究

目的 比较膨胀式椎弓根螺钉(EPS)与骨水泥(PMMA)强化方法在体外提高螺钉稳定性的效果.方法 将60个新鲜成年绵羊腰椎随机分为三组.普通椎弓根螺钉组(CPS组):直接拧入普通椎弓根螺钉;PMMA-PS组:向钉道内注入PMMA(1.0 ml)后拧入CPS;EPS组:直接拧入EPS.24 h后对所有标本进行X线检查,随...     

3种椎弓根螺钉置钉方式治疗无神经损伤的胸腰椎压缩骨折疗效比较

目的比较经皮、经椎旁肌间隙(Wiltse入路)与传统开放3种椎弓根螺钉置钉方式治疗无神经损伤的胸腰椎压缩骨折的疗效。方法将148例单椎、无神经损伤的胸腰椎骨折(AO分型A型)患者根据手术方式不同分为A组(采用经皮椎弓根置钉,67例)、B组(采用Wiltse入路置钉,45例)、C组(采用传统开放置钉,36例)。比较3组手术情况、疼痛VAS评分及影像学参数。结果患者均获得随访,时间12~24个月。手术时间3组比较差异无统计学意义(P>0.05),术中出血量A、B组少于C组(P<0.05),X线透视次数A组多于B、C组(P<0.05)。术后1周及末次随访时,伤椎后凸Cobb角A组大于B、C组(P<0.05),伤椎前缘高度百分比A组低于B、C组(P<0.05)。术后3个月腰痛VAS评分A、B组低于C组(P<0.05)。结论3种椎弓根螺钉置钉方式均是治疗胸腰椎压缩骨折的有效方法,经皮椎弓根置钉和Wiltse入路置钉具有创伤小、患者恢复快、术后腰部疼痛程度轻的优点,但经皮椎弓根置钉术中医患放射线曝露时间长,椎体高度恢复及后凸角度恢复略差。     

Morphological character of cervical spine for anterior transpedicular screw fixation

Background:

Anterior cervical interbody grafts/cages combined with a plate were frequently used in multilevel discectomies/corpectomies. In order to avoid additional posterior stabilization in patients who undergo anterior reconstructive surgery, an anterior cervical transpedicular screw fixation, which offers higher stability is desirable. We investigated in this study the anatomical (morphologic) characters for cervical anterior transpedicular screw fixation.

Materials and Methods:

Left pedicle parameters were measured on computed tomography (CT) images based on 36 cervical spine CT scans from healthy subjects. The parameters included outer pedicle width (Distance from lateral to medial pedicle surface in the coronal plane), outer pedicle height (OPH) (Distance from upper to lower pedicle surface in the sagittal plane), maximal pedicle axis length (MPAL), distance transverse insertion point (DIP), distance of the insertion point to the upper end plate (DIUP), pedicle sagittal transverse angle (PSTA) and pedicle transverse angle (PTA) at C3 to C7.

Results:

The values of outer pedicle width and MPAL in males were larger than in females from C3 to C7. The OPH in males was larger than in females at C3 to C6, but there was no difference at C7. The DIP and PTA were significantly greater in males than in females at C3, but there was no difference in the angle at C4-7. The PSTA was not statistically different between genders at C3, 4, 7, but this value in males was larger than females at C5, 6. The DIUP was significantly greater in males at C3, 4, 6, 7 but was non significant at C5.

Conclusions:

The placement of cervical anterior transpedicular screws should be individualized for each patient and based on a detailed preoperative planning.     

Comparison of unilateral versus bilateral pedicle screw fixation in lumbar interbody fusion: a meta-analysis

Purpose

This is a meta-analysis to compare the clinical results between unilateral and bilateral pedicle screw (PS) fixation in lumbar interbody fusion.

Methods

We included published studies with no language and year restrictions. The criteria which Koes et al. designed in 1995 were used to evaluate the risk of bias of the included studies. All data were analyzed by Review Manager 5.1. The primary outcomes included fusion rate and screw complications, and the secondary outcomes were operative time, blood loss, and hospital time.

Results

A total of five prospective studies with 407 patients were included in the current meta-analysis, and four of them were randomized controlled trials. There was no significant difference between unilateral PS fixation and bilateral PS fixation group in fusion rate and screw complications (fusion rate: OR 0.54, Z = 1.33, P = 0.18, I ² = 0 %; screw complications: OR 1.45, Z = 0.71, P = 0.48; I ² = 44 %). In the secondary outcomes, the operative time (Z = 3.35, P = 0.0008; I ² = 95 %) and blood loss (Z = 4.35, P < 0.0001; I ² = 98 %) was significantly higher in bilateral PS fixation group than in unilateral PS fixation group. Besides, no significant difference was found in hospital time (Z = 1.19, P = 0.24; I ² = 99 %).

Conclusions

In our meta-analysis, we found that unilateral PS fixation in lumbar fusion was as effective as bilateral PS fixation for lumbar degenerative diseases without major instability, no significant difference was found in hospital time, fusion rate and screw complications. In terms of operative time and blood loss, unilateral PS fixation even produced better results.     

短节段椎弓根螺钉内固定结合伤椎植骨植钉术在胸腰椎骨折的应用

目的：比较短节段椎弓根螺钉内固定结合伤椎植骨植钉术与跨节段椎弓根螺钉内固定术治疗胸腰椎爆裂或压缩骨折的临床疗效。方法将46例胸腰椎爆裂或压缩骨折患者随机分为2组,分别使用短节段椎弓根螺钉内固定结合伤椎植骨植钉术和跨节段椎弓根螺钉内固定结合伤椎植骨术治疗。比较两组手术时间、术中出血量、术后Cobb角、伤椎前缘高度压缩率、椎间隙高度丢失、神经功能恢复（Frankel分级）、JOA评分及VAS评分。结果两组患者手术时间和术中出血量比较,差异均无统计学意义（P〉0.05）。术后12个月神经功能Frankel分级差异无统计学意义。术后各时间点观察组、对照组Cobb角、各椎间隙高度、VAS评分及JOA评分比较差异无统计学意义（P〉0.05）。结论短节段椎弓根螺钉内固定结合伤椎植骨植钉术治疗胸腰椎爆裂或压缩骨折能有效恢复并维持伤椎高度,但不能有效地防止相邻节段的退变和后凸畸形矫正度的丢失。     

寰枢椎椎弓根螺钉置钉技术的临床应用

目的：探讨寰枢椎椎弓根螺钉置钉技术在上颈椎损伤临床应用的效果。方法选择性应用寰枢椎椎弓根螺钉固定技术治疗 Jefferson 骨折5例,齿状突骨折11例,Hangman 骨折9例。结果术中无椎动脉、脊髓及神经根损伤发生。1例暴露时损伤静脉丛,予以压迫即能止血;1例寰枢椎骨折不完全复位。患者均获随访,时间1～2年。患者临床症状明显改善,术后1年行 X 线及 CT 检查,显示所有骨折均骨性愈合,螺钉位置良好,无松动、断钉。结论寰枢椎椎弓根螺钉内固定技术具有固定可靠及骨折愈合率高等特点,为上颈椎损伤提供了坚固的稳定性。